Use of substituted phenylenediaminealkyl halide condensation products of antiozone agents in rubber



- through the nitrogen atoms.

l atent OF SUBSTITUTED PHENYLENEDIAMINE- ALKYL HALIDE CONDENSATION' PROD- UCTS OF ANTIOZONE AGENTS IN RUBBER Harry E. Albert, Lafayette Hill, Pa.', assignor to The Firestone Tire .& Rubber Company, Akron, Ohio, a corporation of Ohio I No Drawing. Original application Nov. 23, 1960, Ser. No. 71,148. Divided and this application Feb. 24, 1964, SerQNo. 364,346

g 10 Claims. (Cl. 260-453) This application is a .division of my application Serial No.- 71,148, filed November 23, 1960, which latter application was a continuation-in-part of my applications Serial No..47l ,898 filed November 29, 1954, and Serial No. 681,873, filed August 27, 1957,'both of which lastnamed applications are abandoned. if,

This invention relates to the use of new cheh lical compounds in inhibiting the deteriorating action of ozone on rubber compositions such as those containing natural rubher, a synthetic rubber homopolymer of butadiene or isoprene or other alkyl derivative thereof, or acopolymer of butadiene or an alkyl derivative thereof with another such diene or a vinyl copolymer, or a mixture of any of these rubbers. Such rubbers are widely used in tires, inner tubes, rubber thread, and products produced from rubber latexes and other rubber articles. v

The deterioration of rubber is due to various factors and is evidenced in various ways. The inhibi-tors'of this invention have been found to absorb or destroy ozone,.

and alkenes containing 2 to 12 carbon atoms, dihalocycloalkanes and dihalocycloalkenes containing 5 to carbon atoms, and phenyl-, alkylphenylqchlorophenyland dichlorophenyl-substituted dihalo alkanes and alkenes containing 8 to 12 carbon atoms. The reactive halogen substitutentsare on different carbon atoms and may be chlorine or bromine or iodine.

The dihalogenated reactants link the phenylenediamines The phcnylenediamine molecules each'contain two replaceable hydrogens and the di- 4 halogenated reactants can combine two or three or four or five or more of these molecules into a single compound. In the condensation products there is no hydrogen on the internal nitrogens.

Assuming the dihalogenated reactant to have the for- I mula Hal.X.Hal', in the condensation product the molecular ratio of the phenylene group prcsent'(regardless of its substituents) to X is 2:1 to 5:4-

,It is known that certain substituted phenylenediamines act as antiozone agents when mixed with a rubber composition. The advantages of the compounds of the present invention over the parent substituted phenylenediamine compounds from which they are derived are: de-

cyclohexyl, methylcyclohexyl, and alkyl groups oil to 10 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, sec-butyl, n-butyl, t-butyl, n-amyl, sec-amyl, tamyl, n-hexyl, sec-hexylQt-hexyl, n-heptyl, t-heptyl, secheptyl, n-octyl, tt-octyl, sec-octyLn-nonyl, sec-nonyl, tnonyl, n-decyl, sec-decyl and t-decyl. R is an alkyl group of 1 to 10 carbon atoms or a cycloalkyl group of 5 to 7 carbon atoms. The substituent groups-can be the same or different. The following compounds are illustrative:

N,N-dimethyl oand p-phenylenediamines N,N'-diethyl oand p-phenylenediamines N,N'-di-isopropyl oand p-phenylenedia mines N,N'- di-sec-butyl 0- and p-phenylenediamines N,N -di-sec-octyl 'oand p-phenylenediamines N,N'-dicyclohexyl oand p-phenylenediamines N-methyl, N'-ethyl oamp-phenylenediamines N-ethyl, N'-t-butyl oand p-phenylenediamines N-methyl, N'-cyclohexyl 0- and p-phenylenediamines N-tt-octyl, N-cyclopentyl oand p-phenylenediamines N-t-butyl, N'-(o-tbutyl-p-ethyl) phenyl oand p-phenylenediamines N-sec-octyl, N-alpha methyl-(p-methyl) benzyl 0- and pphenylenediamines N-cyclohexyl, N'-alpha-methylbenzyl oand p-phenylenediamines N-isopropyl, N-benzyl oand p-phenylenediamines N-methyl, N'-tolyl oand p-phenylenediamines N-cyclohexyl, N'-phenyl oand p-phenylenediamines N-lsopropyl', N'-phenyl oand p-phenylenediamines 'N-sec-octyl, N'-phenyl oand p-phenylenediamines N-methyl, N-ethylphenyl oand p-phenylenediamines The following are illustrative of the dihalogenated reactants used in making the reaction products:

Ethylene dichloride, dibromide and diiodide l-chloroQ-bromoethane Propylene dichloride, dibromide and diiodide Trimethylene dichloride, dibromide and bromoiodide Butylene dichloride, dibromide and diiodide Tetramethylene dichloride, dibromide and diiodide Pentylene dichloride, dibromide and diiodide Hexamethylene dichloride, dibromide and diiodide Hexylene dichloride, dibromide and diiodide Octylene dichloride, dibromide and diioide Pentamethylene dichloride, dibromide and diiodide Alpha,beta-styrene dichloride, dibromide and diiodide 1,2-dibromocyclohexane 1,3-dibromobutane 1,2-dibromobutane 1,4-dichlorobutcne-2 2-phenyl-1,2-dibromopropane l-p-tolyl-1,2-dichloroethane 1-(2,4-dichlorophenyl)-1,2-dichloroethane 1-(p-chlorophenyl)-1,Z-dibromoethane Decamethylene dichloride, dibromide and diiodide Dodecamcthylene dichloride, dibromide and diiodide 1,2-dibromobutene-3 1,2-dichloropentene-4 1,2-dichloro-3 -methylbutene-3 1,4-dichlorobutene-2 l,4-dibromo-2,3-dimethylbutenc-Z 1,2-dichlorocyclopentene-3 1,4-dibromocyclopentene-2 1,4-dibromo-2,6-dimethylheptene-2 2,3-dich1oro-2,6-dimethyloctene-6 severely toxic and sensitizing agent.

butyl-p-pheny-lenediamine which is well known to be a I This is-prefer'ably reacted with ethylene'dichloride or-ethylene dibrornide.

whcreCJl, is :1 secondary butyl group.

REACTION NO. 2

The above reaction waslvrepeated, using 330 grams (1.5 moles) .of N,N'-di-secbutyl-p-phenylenediamine, 79.5 grams (1.75 moles) of sodiumvcarbonate in 750 ml.

Both halogens are replaced during the reaction, and the I hydrogen" halide produced is neutralized by any alkaline f gg ig 22 3 gi'b ggi g 3, 33? g g z g igig neutralizing Ordinarily: employed for neutralizing 1 grams of this material was distilled under reduced preshydmgevn halide pfoduced in conqensafion reaptionssuch sure until the unreacted material was removed (up to 140 as sodium, pota sium, or antmonl y 9X d C t 1 mm) The distilled material weighed 20 g ams f meaty-Hate pgmsphaiedandtthi cotndenga- 10 (2 8.5 perceht The residue (50 gramslwa's' a dark ion 'reao ion can e carrie on aany empera ure e 1 I tween roointerhperature and therefiuxing temperature of brown liquid and 5f .9

i the aqueous reaction mixture, at atmospheric, subatrnos- REACTIONNO' 3 pheric orsuperatmospheric pressure. Compounds or mixa a of compqmds of difierent mplegular R areob .In the foregoing reactions the 'Phenylenediamine and tamed' s' condcnsafiol} P!" 0511?? may-wmintwo ethylene dib'romide were reacted in the'ratio of 2:1. In to five P e di m pe f I this third reaction an excess of 45 percent of ethylene di- The followlng reactions arelllllustratlvei bromide over that required for the 2:1 ratio was em- Y REACTION N 2o g 'h am t l )'fNN'-d' our un r or -y rams mo es 0 i-sec- Four l l ff fl (2 10195) of butyl-phen'ylenediaminegand 154 grams (1.45 moles) of butyl'p'phFnylenedlamme. (1 mole) of anhy sodium carbonate in-l liter of water were heated to redrous sodium carbonate m one llter of water, and 188 flux and than 273 grams (L45 moles) of-e'thylene dibn} 'grams mole) ethylene dibiromiyde were heated at mide was added over an hour period. The reaction mixrefluxfor hours iaiqueous a ture was refluxed 5 hours. The aqueous layer was rerfmm coplfidmeactmnQmlxmm anddlscafdeq' moved by decantatioh andthe non-aqueous layer was organ c layer was takenup m ether, the ether solution-was treated wimzoo ml of petroleum ether 1 liter of math washed twice with water, treated withdecolo'rizing carbon, anol and 00 of 'iSopropanoL It wasanOWed to sand i f l fi f g fg y, the 1 one day' to crystallize. It'was filtered, the crude crystal- 0 owe a? i -1 2 o m ig line material weighing 200 grams. This crude product.v gig; g f ff g gg g f zg g g jz was dissolved in toluene and precipitated by alcohol. It was then recrystallized from 'n-hexane n-heptane mixture. Distillation of grams of Product A at 1 mm. pressure The purified pmductweighed rams and mclted at gave-the following fractions, to several ofwhich reference C A portion further g by recrystalliza lpade below d thcse am identlfied by pmductdesig' 35 tion from hexane-methanol for :nalys'is, had a melting. m point of l17122' C.. and herein is designated as Product Fraction i Boiling point I Grams Percent Designation the following 1 o h' analysis b to 146 C 8 Product G with the analysis calculated for the compound to s 7 I 1 conta ning 4 'phenylenediamme nuclei to 3 ethylene to 245C...*. 4,5 I 6.4 Product B. bridges: I 245 to 265 0---- 25. 3 35. 7 Product 0. Residue 20.0 28.2 Product D.

On standing the 'crude condensation product crystallized. 45 On extraction with petroleum' ether, '50 grams of crude ggy gfig Eggs; productfgave 11.5 grains (23 percentyield) of crude solid. After extraction with methanolthis product was i Came 77.62 "33 recrystallized from isopropyl-' alcohol and then from Hydrogen--. 10.72 10. 5a n-hexane,'to. yield a product having a constant melting 5O %%:;};-gim git ii ioit i point of 109 to -113 C. This. product is designated as Active y o e 0.21 0.20

ProductEherein. l v Crystalline Product E was analyzed to determine its structure. --The' data obtained is given'in the following there compared w theoretical for 55 This analysis of Product G indicates that it has the same pd i Product of m .9 phenylenedla' structure as Product E, the higher melting point probably wi i mvolesyof a being caused by a slightly higher degree of purity.

. 1 v N,N'-di-sec-butyl-phenylenediamine was reacted with ig g fif; fg gg ethylene dibromide using various excess percentages of I Q the latter, employing the general reaction as set forth in Carbon 77,62 77,54 more detail in the foregoing. In each case the reaction gagggg g mixture was refluxed for 6 hours. The following table Moleculur weigiit zcr 6566i) y J 959:4 1034: gives the yield in each instance. and .adescription of the product. 7 The percent of crystalline solid in the product v was determined'by extraction with petroleum ether. The

The good. agreement between the calculated percentage yield and melting point of the fourth condensation prodco'mpositionand the actual analysis is apparent. Beuct in; this table were determined after. recrystallization cause of this good agreement, it is concluded that this from toluene-methanol and nhexane-n -heptane. This crystalline Product E has the following structure: product will be recognized as Product G of Reaction No. 3. Tine 04H. C Up' C4119 'Qfl'lg C4119 l -1H9 T'lllo once with dilute ammonia and twice with water.

solvent was removed and the residue was distilled up to Table I 1 Reactants N,N-dl-secbutyl- NagCOz (in 100 Ethylene Yield in Percent p-plienyleneml. water) di-bromido grams solid Description Product dinmine I Grams Mole Grams Mole Grams Mole 44.0 0.2: T 12.2 0.115 21.2 0.115 40.5 20 Dargdbrownscmi- 11 so 44.0 0.2 13.8 0.130 24.4 0.130 42.5 Dark brown, I

' very sticky.

44.0 0.2 15. 4 0.145 27. 3 0. 145 46. 40 Dark red-brown J semi-solid.

440 2.0 154 1.45 273 1.45 80 Light reddish G I purple solid.

44.0 0.2 10.5 0.155 29.2 0.155 44.7 Brogan plastic K I so 441.0 0.2 18.6 0.175 32.9 0.175 44.5 48 Brown, plastic L 1 Percent crystalline solid in product obtained. 2 In 1 liter of water. Condensation products with ethylene dichloride are 20 of platinum oxide and 0.2 gram of methyl-i-butyl ketone.

readily-obtained, but require more drastic conditions than those used for dibromide, as illustrated by the following reactions.

REACTION NO. 1

A pressure autoclave equipped with an external jacket having an electrical heater and provided with rocking 'mechanism to permit agitation was charged with 154 grams (0.7 mole) of N,N-di-sec-butyl-p-phenylenediamine, 54 grams (0.545 mole) ethylene dichloride, 5 8 grams of Sodium carbonate, and 350 ml. of water. Heating was carried on for 12 /2 hours at 260 F. After cooling, the gas formed during the reaction was released, and the product was dissolved in a mixture of 250 ml. of heptarie and100 ml. of toluene. The aqueous layer was separated'and discarded, and the organic layer was washed The 170 C. at-8 mm. to remove unreacted N,N-di-sec-butylp-phenylenediamine. The viscous liquid thus obtained is k designatedProduct M. This product was fouhd to have a-molecular weight (cryoscopic) of 444.

Other condensation products were obtained by using difierent mole ratios of N,N'-di-sec-butyl-p-phenylenediamine to ethylene chloride and different reaction conditions. Several such reactions are summarized in the following table. In this table the Mole Ratio is that of N,N'-di-sec'-butyl-p-phenylenediamine to ethylene chloride charged.

" Uurcactedamiuo not removed.

The larger amounts of ethylene dichloride required, compared to ethylene dibromide, to give a product of a certain molecular weight, is undoubtedly caused by side reactions.

' REACTION NO. 5

A mixture of 44.0 grams (0.2 mole) of N,N'-di-sec butyl-p-phenylenediamine, 15.9 grams (0.15 mole) of sodium carbonate in 200 ml. of water, and 3.3 grams (0.15 mole) of propylene dibromide was heated under reflux for 5 hours. The organic layer was separated from the aqueous layer in -a separatory funnel. The unreacted N,N-di-sec-butyl-p-phenylenediamine was removed by distillation, leaving a dark-brown very viscous liquid.

This liquid is designated Product T.

v REACTION NO. 6

f One-tenth mole of p-ethylaminoaniline was dissolved in 100 ml. ethanol in ml. of glacial acetic acid, 0.1 gram Under 3-4 atmospheres of hydrogen two hours were required for absorption of 80 percent of the theoretical amount of hydrogen. The N-ethyl-N-hexyl-p-phenylenediamine produced was worked up inthe usual way and finally distilled. B.P. (3 mm.) 104-105 C.

Two-tenths mole of N-ethyl-N'-hexyl p-phenylenediamine with 0.155 mole of ethylene dibromide and 0.155

' mole of sodiumcarbonate in 100 'ml. of water were heated and stirred under reflux for 6 hours. After extracting with toluene and washing with water the solvent and lowboiling material were taken off in vacuo, the finalpot temperature being 155 C. under 3 mm. of nitrogen. Two determinations of the molecular weight (cryoscopic) of the resulting reaction product of the N-ethyl-N-hexy1- p-phenylenediamine and ethylene dibromide gave 601 and 607. This product is identified herein as Product U.

REACTION NO. 7

n-Butylaminoaniline was alkylated with cyclohexanone under the conditions set forth for alkylation of p-ethylaminoaniline (above). 'The theoretical absorption of hydrogen occurred in 20 minutes to produce N-n-butyl-N'- cyclohexyl-p-phenylenediamine. B.P. (3 mm.) 164- 166 C.

The condensation product of N-n-butyl-N-cyc1ohexy1- p-phenylenediamine and ethylene dibromide was prepared in the same manner as in Reaction No. 6, except that 0.166 mole each of ethylene dibromide and sodium carbonate were used. The molecular weight (cryoscopic) of the product was 1150. This product is identified herein as Product'V.

Products U and V showedantiozonant activity.

Various of the phenylenediamine derivatives are known to be toxic and to sensitize the skin. This is particularly true of N,N-di-sec-butyl-para-phenylenediamine which ing, or substantially so.

'tained stretched at 12.5 percent elongation.

The inhibiting effect of the condensation products of this invention on the action of ozone on rubbers was determined with /2 inch dumbbell strips of approximately 0.100 gauge thickness. These were exposed to ozone, the apparatus and 'method ofdetermining the ozone consumption being described in the articles by Ford and Cooper appearing in India Rubber World 124, 696 (September 1951), and 125, 55 (October 1951), entitled A Study of the Factors Affecting the Weathering of Rubber- Like Materials, I and II. In the tests the ozone, concentration was maintained at 60. parts per 100,000,000 parts of air, as indicated. Two types of tests were conducted. In one type called the dynamic test, the sample was repeatedly stretched between the limits of 0 and 20 percent elongation at the rate of 108 cycles per minute. In the other type of test, the static, the samples were main- Usually the samples were exposed for seven hours at F., al-

I identical cor'uzlitions.

the size and numberof the cracks in each sample were compared visuallywith the size and number of the cracks Lin 3. Iblank which contained no antiozone agent and was tested at the same" time as the test' sampleand .under "An arbitrary scale of ,r neasuring' the results was adopted.

' T hesize ot the cracks wasrated as very fine, fine, medium,

'lowting'table's:

The blank forthephysical testsand testsrforantio zone 1 activity in GR-S (also known as 'SBR) treaId stoclt was 'mula uSing-Z'parts by weight for. each 100 parts by weight of .GR-S.x; The rubber compositions were mi'xedin; the

of very coersiand the'number of'the prackswas '10 usual manner, and slabs' wcre cured or vulcanized in 1 e none very w m d m?" 'nf i to the usual manner. Testidata obtained ,on strips cut from numerous drF X n m u -(W the vulcanized 'slabs are recorded inthe following tables. I Rubbef'comPositions contaiflinglhe condensatwn. P .In th e' followin tables Tensile? is used for. tensile -ucts were tested for physical properties as well -as,for.- strength; y r n strength mtem'iqn, -thei-r antipzone activity,"with results recorded in the foland fE, .R ten,"' f do ti tenti n, I Th t il strength retention and elongation retention are expressed as percentages, as is the elongation. The modulus and t'en's'ile-strength'are' given pounds per. square inch;

Table 2 Blank Samplel Sample2 Sample3 Sample4 2 --2 Product I I 2 159.4 161.4 161.4 161 4 161.4 4 (CUREDSO'A'I 280, F.)

' Normaltenslle Properties: I

- 300% modu us- 850 775 725 725 750 Tensile. 3,250 3, 350 3,300 3,400 3,225 Elongation [600 "625 '655 660 655 Aged 2daysln oven at 212 F.: r I 300%-rnodulus-... 2,000 1,650 1, 550 1, 625 1,525 ensi1e 2, 350 2, 825 2, 900 2, 850 2,975 1 T S. .Reten .72 84 88 84 02 .Elongatlon. 335 415 140- .420 450 E. Reten '56. 68 67 .64 69 Ozone exposure: I hrs.,.60 p.p.h.m., 95 F.- 1 Statle,stze.- Fine Y Frequency Num- None None None None I Dynamic, 1 .Flne Frequenc Nurn NDllB, None None None 7 hrs., 60 p.p. '.rn., 95 F. I I e i Statlqslze Coarse Frequency... I None None None None I Dynamic, size Coarse Frequency None None None None I I II Mod-to-num. I a compounded accordmg to the following formula: The results show that 'the' condensation. products of I Parts by we ght N,N'-d1-sembutyl-p-phenylenedramme provide excellent GR-S '=.100 protecti1on. 1 I I Channel black v I Further-test results are grven m the following-tables.

H Tabl e3= Blank Sample Sample Sample Sample i 6 I 0 7 8 Blank 159.4 159.4 159.4 159.4 Product A 2' Product H I 2 Product 2 Product J. I 2

CURED AT 280 F.

Normaltensllt a properties' I 300% .mod us 750 7 775 7150 725 Tensllenn; -3, 250 3, 550 3, 450 3, 500 3, 400 Elongatio 615 650 640 I 635 635 Aged2 dayisln over at 212 300% A odulus 1,875 1,625 1,600 1,600 1,600 Tenslle 2,125 2,700 2,575 2,775 I 2,825 'T.S. Retell- .66 76- I 75 79 I Elongation. 345' 425 .410 Y 450 455 E. Reten..- Y -65, 64' 71 Ozone exposure:

3 lirs., 60 p.p.h.m. F.'.- I

-. Statle,slm Medium 2 Frequency... Num. None None None None Dynamic, size Medium Frequent: Num. None None None None 7 hrs., 60 pp. I I

Static, slze Coarse Frequency 0) None None None I N one Dynamic, slze Coarse Frequency N um. None None None None 1 Mod. to N um.

-T able 4 Blank Sample Sample Sample Sample Blank 159.4 159.4 150.4 159.4 159.4

ProductA 2 4 Product-F (stripped by distillation)- 2 ProductK 2 v Product 11.. 2 I

01112111) 80' Ar 280* F. Normal tensile Properties:

u Modu us 7 725 725 700 675 cnsl 3,150 3, 525 3,550 3, 475 3, 500. Elongatio 620 635 035 630 625 Aged 2 days in en 300% Modulus- 1. 900 2, 000 1, 900 1, 925 Ten 19 1,925 2,700 2, 750 2,875 2,025 T.S. Reten 61 77 77 80 75 Elongation 280 385 395 395 375 E.Reten; 45 61 62 63 G Ozoneexposureflhrs 60 j Stat c, size-.. Coarse Frequency. Nnm. None None None None Dynamic, Medium Frequency.. Nnm. None Uone None None Table 5 The physical properties of Product C were compared with those of the parent material, N,N-di-sec-butyl-p' 1118111; sm r ne 521111111110 phenylenediamine', in a black sidewall tire stock of the fol- I lowing formula:

- Parts by weight Blank Product T. GRS 88.5 m Elastomeric plasticizer 22.9-

159.4 161.4 161.4 Carbon black 42.0 CUBED AT F Zinc oxide n--. 3.0 N u O11 softener 10.0 orma nsre ropcr es:

' odu us -1 750 650 775 5 Antloxldam g m i e 2.288 ,2 2 g? Sulfur r 2.0 onga on T 6 Agegog duly/1s inlovcn at 212 F 2 5 1 r" 1 (F5 Accegrator o u us 1 o I "rensneu 2,550 2, 930 3,225 Pam m wax T5. Reten .91' as s0 I Elongatiom 3 0 4 0 470 1 The antioxidant is a. mixture of 2 2,4-trlmethy1-6-pheuyl- E. Bcten 5,4 67 73 1,2-d1hydroqu1nollne and N,N-dlpllenyl-rrp enylenedlannne.

Ozone exposure, 4 hrs. up. 1.11.1.

m Two parts of N,N-di-secbutyl-p-phenylenediaminefand };requency.i. Nlnm None None the respective test materials were added for testing.

ynarrnc $20. 1 euurn Frequenc'y None None These stocks were cured 60 mlnu tes at 280F. and

. found to have the followmg propernes:

Addition None Parent Product 0 material Normal tensile propertic sz' 3009",v modulus 600 575. Tensile 1,500 1,600. Elongatiom 690 640. Aged 2 days at 212 4 Tensile 1,375 1,425.

Elongation 3'20 320. 'I.S. Rotcn 91.5 88.5. Ozone exposure, 7 hrs. 60 p.p.h.n1. 280

swims-no No cracking No cracking Nocrackiug Dynamic Many cracks Few edge Few edge medium cracks cracks size. only. only. Heavy..." Trace. Bloom (shelf aged 15 days) None gg efi Bloom Both condensation products gave'exeellent results. Antiozone activity on one stock was determined by a static test, with the-stock exposed to normal sunlight outside while elongated 12 /2 percent. The results are recorded in the following table:

These data show the reaction product of ethylene dibromide and N,N'-di-sec-butyl-p-phenylenediamine to give ozone protection fully equivalent to that'given by the parent compound without the objcc'tional bloom given by the latter.

28 daysQIuly 29-August 26 2' months-July 29-September 28 Back l 1-1 Productwas evaluated in natural rubber the tread stock of thefollowin'gcomposition:

I carboiiradicai. An exampleof this type 12 I "1 l I of curing agent isthe resol formed by condensing a l excess of stituted ph'e'nylene'diamines, etc., as is known in' the art.

curahlercsin, such as a phenol-aldehyde .rcsol or even the monomeric dimcthyloh or' I poiymcthylol phen-ol; ,T he phenol is advantageously nuclcai'ly substituted by ahydro.

:Rubbers arecurcd'also by heating admixed with a I Parts by weight formaldehyde with p-tt-Io'ctylphenol in they presence of an Smdked Sheds 10.0 alkaline catalysti Y I Softener I '4 5 By sulfurvulcanization is. meant the curing of rubber- Stearie acid Y 3 by reaction with either free;s'ulfun.ora vulcanizing' agent Zinc. oxide 3 of: the'sulfu-r-donor typeu Know n agents of the latter AcceleratorI L. '1 type include the various phenol polysulfides including Sulfur 3 the alkyl derivatives-thereof, thexarithogen' polysulfides, .Carbo'n black 50' 50 the jthiura'rn disulfides and; polysulfides, various amine I sulfides'including'the dialky'lamine polysulfides'andreacv '164 tion products of primary amines ,with excess sulfur.

Table 6 I Control I Wax control Test I Blnnlr r 164 164 I 164 Wax 3 I 3 Product 0- 2 CURED 60' AT 280? I".

Normal tensile roperties: I 1 400% Moduus I 8,100 2,90 2,525.. Tensile strength 3,075 3,850.- 3,950. Elongation... 480 480 Aged 2 days at 212 F Tensile strength.. 1,77 1,625 2,025.

,Elongatlon I am I "270 'Ozoue exposliro,,7 hrs. 60 p.p.h'.iu. 95 F.: L

Static, sim Flue. Medium.-.. None.- Fm Numerous Moderate--. None. v Dynamic, size- I Fine. Fine-" V. Fine. Frequency-.. Numerous Numerous" Numerous; Mixed ozone test 10 hr's.60p at 95F Size.'.. I Medium.. Medium-- -V.Fine.

- Fre'quency.. Numerous --Numerous. Numerpus.

. The Mixed Ozone Test" was-conducted partially under Known vulcanization, accelerators are useful in speeding static conditions and partialIy under dynamic conditions. up the vulcanization process and operative herein, espe- The results of the foregoing test show, that in all the cially the relatively active accelerators including the r ozone cracking tests, a stock containing Product Ojplus thia zole sulfenamides, 'e.g'.,"N-cyclohexyi-2-benzothiazole- '3 parts ofwa'x is better than a blank stock containing no sulfenamide, 'thiazoline I sulfenamides, 'thiocarbamyl suladditive or such stock containing 3 parts of wax aloneifenamides, mercaptothiazolesf. mercaptothiazolines, thi- Although" the testresults refer to the use of the novel. azolyl monoand disu'lfides, the N,N'-'disubstituted di-' condensation products with natural rubber and GR S, the thiocarbamates, the thiuram sulfides, the xanthogen sul-. invention includes the use of the'antiozonants with any ,fides,- and metallic 'salts of mercaptothiazoles-or mercaptodiene rubber,- including hoIfiOPolymers and copolymers' of. thiazolines or'idithiocarbar'nic' acids. I conjugated hydrocarbon dienes, copolymers' of such con-1 One-ormore accclerator'activatoris often used with juga'ted dienes and ethyle'nicaliy unsaturated monomers, any of the accelerators mentioned, and such activators inand mixtures'thereof, including butadieneisoprerie COpOl- I I I clude the ,various derivatives of 'guanidine known in the ymers and frubben identified under. ASTM designated 'rubberart, amine salts of inorganic and organic acids, -Dl418 -56Tinthe1956'Journa1'as NB R, ABR, PBR and various amines themselves,- and alkaline salts such as SIR'andespecially naturalz-r llbb f, 5BR, -IR and HR, sodium acetate and the like, as wellas other activators etc. I I v v a 5 known in the art. Additionally, two or more accelerators Crosslinked, cured or VlllCalllZ (1' l'l1bbf is a rubber or accelerator combinations'are sometimes desirable "in I made less soluble, less thermoplastic and more elastic by a a si gle -rubber compound. II Many of the accelerators crosslinking. cro i of ng can be accomplished mentionedfaboveare suitable in :latex formulations, espey y known closslinking- 8 m m l o l ciall'y such common acceleratorsas piperidinium penta ca be cured by heating it with'su fu 0 Smith-bearing 1 methylene dithioearbamate, zinc butyliranthate, zinc n agent. Preferably in thepresence-bf a suitable ethylxanate, zinc salt of mercaptobenz'othiazole, zinc dib d ihiSPTOCBSS iSY'WCll known fll ii aft methyldithiocarbamate, and' zinc dibutyldithiocarbamate. as fur c Other curing agents such vas "Although vulcanization is usually accomplished by heatselenium or tellurium'can be used in C nj ct th mg a vulcaniz'able rubber, composition at a temperature replacing sulfur. I in-the 'range'of 240 to 400 F. foratirne ranging from A di feren c s of u n ag n s t q q s I several hours to a. few seconds,'vulcanizationof a suith 1 known diVOI' P yp un fl fl able activatedfrubber composition can take place at lower .oximesandderivatives thereofand qu-inone anil's, diand t jtu h i ordinary room t'l'e m I For P y-ni o p n 1115-. pq yo' d example, alatexifilm containin'ga sulfur curing agent and a pou d i i fi pg r 65 an activated ultra" accelerator can be cured by'allowing including dwumyl 'PerOXlde, mp h g f the film to remain at room temperature for several hours is usually heated withthe, curinga'gents to effect .the or afew daysr I I ideslzred n'sr is n, h art-- h p 'o I The above data show that the phenylenedi'amine' deriva- Cllfmg ag ts P bY'. i Q tives of the invention possess a number of unobvious mp red" Iead'(P aQ4), 10 dlflflllspce'flam sllb-v advantages-overtime corresponding dia'mines. A small amountuotitheantiozone agent, between 0.005 and 10 parts by' weight per parts of. the rubber, is effective.

The agent is also effective, especially at the. lower'conccntratiorls, as a heat andlight stabilizer in synthetic rubbcrs, c.-g., high cis-polyisoprcne; The combination of a wax with a diamine derivative of the invention protects the various rubber compositions much more effectively against ozone than any. of the materials employed in r r r and R! R! i sari in which I X is a member from the class consisting of alkane groups containing two to twelve carbon atoms, cycloalkane groups containing five to ten carbon atoms,

and phenyl-, alkylphenyl-, chlorophenyland dichlorophenyl alkane groups containing eight to twelve carbon atoms,

R is a member from the class consisting of phenyl,

alkylphenyl radicals in which each alkyl group contains-one to siX carbon'atoms, cycloalkyl radicals each containing five to seven carbon atoms and alkyl 1 radicals each containing one to ten carbonfatoms, Ris a memberfrom the class consisting of alkyl radicals containing one to-ten carbon atoms and cycloalkyl radicals containing five to seven carbon atoms, and n is a number from the group consisting of 0; 1, 2 and 3, and is zero when R is of the class consisting of phenyl and valkylphenyl'.

2 The composition of claim 1 in which the composition of the antiozonant is represented by the first of the two structural formulae there given.

3. The-composition of claim 1 in which the composition of the antiozonant is represented by the second of thetwo structural formulae there given.

4. A diene rubber composition which includes an antiozonant' amount of an antiozonant of the formula in which v R is an alkyl group of one to ten carbon atoms, and

n is a number from the group consisting of 0, 1, 2 and 6 i v 0 1 X isa member from the class consistingof alkane groups containing two to twelve car'bon'atorns, cycloalkane groups containing five to ten carbon atoms, and phenyl'-, alkylphenyb, chlorophenyland dichlorophenyl' alkane groups containing eight to twelve-carbon atoms.

Ris a memberfrom the class consisting of. phenyl,

alkylphenyl radicals in which each alkyd group contains one to six carbon atoms, cycloalkyl radicals each containing five to seven carbon atoms and alkyl radicals each containing, one to ten carbon atoms,

R' is a member from the class consisting of alkyl radical s containing one to ten carbon atoms and cycloalkyl radicals containing five to seven carbon atoms,

- and n is a number from the group consisting of 0, l, 2 and 3, and is zero when R is of the class consisting of phenyl and alkylphenyl. I

f 7 The process of claim 6 in which in the composition vof the antiozonant is represented by the first of the two structural formulae there given.

8; The process of' claim 6 in which in the composition of the antio gonant is represented by the second of the two structural :formulae there given. I 9. The process which comprises vulcanizing a diene rubber in the presence of an antiozonant amount of an antiozonant' having'the formula in which i R is an alkyl group of one to ten carbon atoms, and n'is a number from the group consisting of 0, 1, 2 and r r r r r pHi N [tCmCIH N mang I 7 ll i 10. The process of claim 9 in which in the formula for the antiozo'nant each R is sec-butyl.

References Cited by the Examiner UNITED STATES PATENTS 3/55 Hill et a1. 260.45.9 2,072,596 3/57 Jones 260809 2,939,867 6/60 Ambelany 260-459 FOREIGN PATENTS 483,605 4/38 (H'cat llrit. |in..

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,208,967 September 28, 1965 Harry E. Albert It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

In the heading to the printed specification, line 3, for

"OP" read AS column 9, Table 5, first column, line 10 thereof, for "300" read 300% column 12, line 56, for "ethylxanate" read -'ethy1xanthate column 14, line 21,

for "alkyd" read alkyl line 70, for "Ambelany" read Ambelang Signed and sealed this 25th day of April 1967.

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents 

1. A DIENE RUBBER COMPOSITION WHICH INCLUDES AN ANTIOZONANT AMOUNT OF AN ANTIOZONANT SELECTED FROM THE CLASS OF ANTIOZANANTS HAVING THE FORMULAE 